President Barack Obama’s campaign is confident that its ground game will produce the winning margin in November — but while they’re well ahead of Mitt Romney, things are a lot tougher than they were in 2008.

The race is tighter. Enthusiasm is lower. Canvassers face voters disappointed in Obama’s first term. Phone bankers find undecideds seriously considering a vote for Mitt Romney. And they’re facing competition from a joint Romney-Republican National Committee operation that’s deeper and more robust than what John McCain put together four years ago.

In a race this tight, the Obama campaign sees its operation delivering wins in Ohio and other key swing states. Advisers to the president are confident that as long as the polls stay tight, Obama will win — even though the campaign won’t say much about its operations, arguing it doesn’t want to reveal too much to opponents.

“The best field operation generally can put an extra 2 or 3 points on the board,” said Steve Rosenthal, a Democratic grass-roots consultant. “Whoever has the best field program, that could be the difference.”

Even as the Republican efforts are posting milestone numbers, the Obama campaign won’t say anything beyond pointing to what campaign manager Jim Messina cited in his Democratic National Convention speech as he explained how much further ahead they were than 2008: 44 million phone calls, 3.8 million door knocks and one million new voter registrations.

The Romney-RNC numbers by last Saturday are larger: 45 million voter contacts by last Saturday — up from the 24 million Bush-Cheney 2004 benchmark. They say they’ve knocked on 9 million doors — three times more than at the same point in 2008. But that total includes knocks that went unanswered, where volunteers left pamphlets for residents, which the Obama campaign doesn’t include in its totals.

None of the claims on numbers of contacts by either campaign can be independently verified.

In terms of volunteers, the Romney-RNC ground operation says 119,000 volunteers have been active since the spring. The Obama campaign won’t say how they’re doing compared to the 1.5 million they had in 2008.

The Obama campaign also points to an email list of tens of millions and a network of volunteers in at least the hundreds of thousands. A constant stream of large campaign events — rallies for thousands featuring the president and, this week, concerts headlined by Bruce Springsteen and Bill Clinton — bring in more data.

“If you think about what we’re doing on the ground the next 14 days, it’s quite simple. We have two jobs: one, to persuade the undecideds, and two, to turn our voters out,” Messina said Tuesday.

At events, the campaign collects names and contact information for supporters, signs up new volunteers, registers voters and gets them to pledge to vote. With early voting under way in many battlegrounds, volunteers are directing rally-goers to their polling places.

“This is something we’ve been working on for five years — our volunteers know these communities,” said Obama national field director Jeremy Bird. “They’re owning the campaign.”

“[James] Carville used to say, ‘It’s the economy,stupid,’ but this year, it’s the network, stupid,” said Joe Trippi, the Democratic consultant who in 2004 helped Howard Dean build his grass-roots machine.

In the past three months, 95,000 more Democrats than Republicans have registered in Colorado, Florida, Iowa, North Carolina and Nevada. Democrats have sent in 195,000 more absentee ballot requests than Republicans in these key states.

And then there’s early voting. Democrats have a 55,000-vote lead in Iowa and a 170,000 vote lead in North Carolina. Ohio and Virginia don’t track early voting by party registration, but tens of thousands more ballots have already been cast in districts where Obama beat McCain in 2008.

“In every single battleground state, we’re outperforming where we were in 2008,” Bird argued.

But Republicans say they’ve been eating into that advantage, and even gaining an edge.

“I think we are better than they are,” said Rick Wiley, the RNC’s political director. “This is the best partnership the RNC and a nominee have ever had — it’s just a machine out there.”

On top of all the volunteer involvement on both sides, there are super PACs and other outside groups that are paying field workers. Democrats also have the support of many more unions, which have wide and experienced networks to turn voters out.

Neither campaign takes its opponents’ declarations of ground game strength too seriously, and both easily slip into trash talk.

“I don’t want to harp on their machine because I don’t think they have one,” Wiley said. He noted that Republican volunteers often send in photos of Obama field offices sitting dormant.

One Obama official said that Romney and the RNC “don’t pass the laugh test for organizing,” and questioned the accuracy of the data the RNC has released on total numbers of phone calls and door knocks, stressing that field organizers of either party generally don’t count unanswered knocks as contacts, as the RNC does.

“Too many people exaggerate,” the official said.

While the Obama team won’t engage in direct comparisons on numbers of volunteers or voter contacts, staffers do talk up up their infrastructure advantages, which they’ve been building since 2008. The reelection campaign has more than 800 field offices nationwide — including at least one in every state — while there are about 300 Romney-RNC victory offices, concentrated in battlegrounds. Each Obama office has at least one staffer and serves as a base of operations for phone calls, canvassing and staging events.

Republicans say that having far few offices set up than Democrats isn’t about not having the money or the people to open more offices: In contrast with Democrats, it’s a reflection of their philosophy of smaller government and more independence. “If we wanted to have as many staff and offices, we could do that,” Romney political director Rich Beeson said on a recent press call. Instead, Republicans choose to “work smarter and simpler.”

In Virginia, RNC Chairman Reince Priebus said on the same call, “We’ve matched the Obama campaign volunteer for volunteer, door knock for door knock, and phone call for phone call.”

Terry Nelson, George W. Bush’s 2004 political director, said that Romney’s good performance during the first debate and the continued sense that Obama is vulnerable — even after a less-decisive second debate — have helped engage the Republican grassroots.

“Certainly, having Mitt Romney perform as he did and really give his supporters something to grasp onto in terms of what he wants to do, how he wants to do it is something that will motivate people to get involved,” Nelson said. A continued sense that the race is tight will “keep the enthusiasm up and compound it as we get closer to Election Day.”

Republicans point to the dominant ground operations they’ve built in a few states — in Virginia to elect Gov. Bob McDonnell and in Wisconsin to block the recall of Gov. Scott Walker in 2011 — as signs of strength across all battlegrounds. But not all GOP efforts are so overwhelming. In Nevada, local journalist Jon Ralston said during a recent TV appearance, it’s a Matchbox car sharing the same road as Obama’s Ferrari.

Anne Alston, 70, a neighborhood team leader in Herndon, Va., is one. She’s already stocked up on ponchos in case it rains on Election Day, and signs up her daughter to volunteer when she’s busy with her part-time job.

“It gets to be addictive,” Alston said on a recent Friday. She spent morning registering voters, waiting to hear Obama speak at George Mason University and the afternoon outside a grocery store, doing more voter registration with a group of local high schoolers who, though too young to vote, are determined to help out.

“This is my legacy,” she said.

In some ways, the president’s October poll tumble may have helped.

“It’s harder to get people out to do things if you think the campaign is going to win and doesn’t need your help,” Trippi said. “As good as things looked a few weeks ago it would have been a lot more difficult. Now, every grassroots activist in the Democratic Party believes Barack Obama needs him.”

Obama’s made a grass-roots plea a regular part of his stump speech, asking people to knock on a few more doors for him and make a few more phone calls for him because he needs their help, and that’s the message that’s coming from the campaign staff too.

“Polls will go up, polls will go down,” David Simas, the campaign’s director of opinion research, said earlier this month during a webcast for volunteers hosted on Dashboard, the online hub for Obama organizing. “At the end of the day, polls don’t matter.”

“Work harder than you ever have. Dig in, make the calls, knock on the doors.”

The Obama campaign won’t say much beyond that they’re trying. Instead, they stress public data that show Democrats with an edge in voter registration, and absentee and early voting data in several key states.

“It would be one thing if this was a 7 or 8 point race either way,” Trippi said. “It’s going to be 1, 2, 3 points, if not tied. And there, the Obama grass-roots organizational abilities, the size of their network, is going to do it.”

CORRECTION: An earlier version of this article provided some outdated early voting counts.